Search results for "likelihood"
showing 10 items of 264 documents
Statistical properties of the site-frequency spectrum associated with lambda-coalescents.
2013
Abstract Statistical properties of the site-frequency spectrum associated with Λ-coalescents are our objects of study. In particular, we derive recursions for the expected value, variance, and covariance of the spectrum, extending earlier results of Fu (1995) for the classical Kingman coalescent. Estimating coalescent parameters introduced by certain Λ-coalescents for data sets too large for full-likelihood methods is our focus. The recursions for the expected values we obtain can be used to find the parameter values that give the best fit to the observed frequency spectrum. The expected values are also used to approximate the probability a (derived) mutation arises on a branch subtending a…
Reliability of automatic detection of AHI during positive airway pressure treatment in obstructive sleep apnea patients: A “real-life study”
2021
Introduction: Automatic event detection (AED) of residual apnea-hypopnea index (AHI) by ventilators is a current practice in sleep and mechanical ventilation Units but this methodology has not been validated in an unselected population of OSA patients. Aim of the present study was to assess in a “real-life” condition the reliability of AED during PAP therapy by the in-built software compared to full polysomnography during follow-up. Methods: We enrolled 300 OSA patients (105 F; AHI 45.3 ± 27.8) already on Positive airway pressure (PAP) therapy: 53% of the patients were on CPAP while other modalities were used in the rest of the sample. Results: Overall, the built-in software identified resi…
Uncertainty in urban stormwater quality modelling: The influence of likelihood measure formulation in the GLUE methodology
2009
In the last years, the attention on integrated analysis of sewer networks, wastewater treatment plants and receiving waters has been growing. However, the common lack of data in the urban water-quality field and the incomplete knowledge regarding the interpretation of the main phenomena taking part in integrated urban water systems draw attention to the necessity of evaluating the reliability of model results. Uncertainty analysis can provide useful hints and information regarding the best model approach to be used by assessing its degrees of significance and reliability. Few studies deal with uncertainty assessment in the integrated urban-drainage field. In order to fill this gap, there ha…
Inferring networks from high-dimensional data with mixed variables
2014
We present two methodologies to deal with high-dimensional data with mixed variables, the strongly decomposable graphical model and the regression-type graphical model. The first model is used to infer conditional independence graphs. The latter model is applied to compute the relative importance or contribution of each predictor to the response variables. Recently, penalized likelihood approaches have also been proposed to estimate graph structures. In a simulation study, we compare the performance of the strongly decomposable graphical model and the graphical lasso in terms of graph recovering. Five different graph structures are used to simulate the data: the banded graph, the cluster gr…
Gypsy endogenous retrovirus maintains potential infectivity in several species of Drosophilids.
2008
Abstract Background Sequences homologous to the gypsy retroelement from Drosophila melanogaster are widely distributed among drosophilids. The structure of gypsy includes an open reading frame resembling the retroviral gene env, which is responsible for the infectious properties of retroviruses. Results In this study we report molecular and phylogeny analysis of the complete env gene from ten species of the obscura group of the genus Drosophila and one species from the genus Scaptomyza. Conclusion The results indicate that in most cases env sequences could produce a functional Env protein and therefore maintain the infectious capability of gypsy in these species.
IFN-gamma-induced protein 10 is a novel biomarker of rhinovirus-induced asthma exacerbations
2007
BACKGROUND: Rhinovirus-induced acute asthma is the most frequent trigger for asthma exacerbations. OBJECTIVE: We assessed which inflammatory mediators were released from bronchial epithelial cells (BECs) after infection with rhinovirus and then determined whether they were also present in subjects with acute virus-induced asthma, with the aim to identify a biomarker or biomarkers for acute virus-induced asthma. METHODS: BECs were obtained from bronchial brushings of steroid-naive asthmatic subjects and healthy nonatopic control subjects. Cells were infected with rhinovirus 16. Inflammatory mediators were measured by means of flow cytometry with a cytometric bead array. Subjects with acute a…
Support for the monophyletic origin of Gnathifera from phylogenomics
2009
The monophyletic origin of Spiralia within the metazoan tree of life is supported by many large-scale phylogenomic data. While there is now substantial molecular evidence for Lophotrochozoa being a monophyletic taxon within Spiralia, the phylogenetic affiliations of many other spiralian phyla remain unclear. Here we focus on the question of a monophyletic taxon Gnathifera, which was originally characterized by jaw morphology as comprising the taxa Rotifera, Acanthocephala and Gnathostomulida. Based on a large-scale molecular sequence dataset of 11,146 amino acid residues, we reconstructed phylogenetic trees of spiralian phyla using maximum-likelihood and Bayesian approaches. We obtain the f…
Evolutionary implications of intron-exon distribution and the properties and sequences of the RPL10A gene in eukaryotes.
2013
The RPL10A gene encodes the RPL10 protein, required for joining 40S and 60S subunits into a functional 80S ribosome. This highly conserved gene, ubiquitous across all eukaryotic super-groups, is characterized by a variable number of spliceosomal introns, present in most organisms. These properties facilitate the recognition of orthologs among distant taxa and thus comparative studies of sequences as well as the distribution and properties of introns in taxonomically distant groups of eukaryotes. The present study examined the multiple ways in which RPL10A conservation vs. sequence changes in the gene over the course of evolution, including in exons, introns, and the encoded proteins, can be…
Penalized logistic regression for small or sparse data: interval estimators revisited
2015
This paper focuses on interval estimation in logistic regression models fitted through the Firth penalized log-likelihood. In this context, many authors have claimed superiority of the Likelihood ratio statistic with respect to the (wrong) Wald statistic via simulation evidence. We re-assess such findings by detailing the inferential tools also including in the comparisons the (right) Wald statistic and other statistics neglected in previous literature. In particular, we assess performances of the CIs estimators by simulation and compare them in a real data set. Differently from previous findings, the Likelihood ratio statistic does not appear to be the best inferential device in Firth pena…
XENON100 dark matter results from a combination of 477 live days
2016
We report on WIMP search results of the XENON100 experiment, combining three runs summing up to 477 live days from January 2010 to January 2014. Data from the first two runs were already published. A blind analysis was applied to the last run recorded between April 2013 and January 2014 prior to combining the results. The ultra-low electromagnetic background of the experiment, ~$5 \times 10^{-3}$ events/(keV$_{\mathrm{ee}}\times$kg$\times$day) before electronic recoil rejection, together with the increased exposure of 48 kg $\times$ yr improves the sensitivity. A profile likelihood analysis using an energy range of (6.6 - 43.3) keV$_{\mathrm{nr}}$ sets a limit on the elastic, spin-independe…